1. Field of the Invention
This disclosure relates to an imprinting method, an imprinting apparatus, and a device manufacturing method configured to detect alignment marks for inspecting alignment between a pattern formed by imprinting and a pattern in a shot area on a substrate.
2. Description of the Related Art
An imprinting technology is a technology that forms a pattern formed on a mold on an imprint material on a substrate, and is proposed as one of lithography technologies for manufacturing semiconductor devices or magnetic storage media (Japanese Patent Laid-Open No. 2007-281072). An imprinting apparatus is configured to bring the mold including a pattern surface having a pattern formed thereon into contact with an imprint material (for example, a light curing resin), and causes the imprint material to be cured in the contact state. The space between the cured imprint material and the mold is increased and the mold is released from the imprint material, so that a pattern is formed on the imprint material on the substrate.
With the imprinting apparatus configured as described above, a die-by-die alignment system is generally used as an alignment method between the mold and the substrate. The die-by-die alignment system is configured to detect a plurality of alignment marks formed in a plurality of shot areas formed on the substrate and a plurality of alignment marks formed on the mold from one shot area to another. As a scope of detection of the alignment marks includes a configuration provided with a sensor configured to detect images of marks and an optical system configured to form images of the marks on the sensor.
In the imprinting technology, even by performing the alignment between the pattern in the shot area and the pattern surface of the mold on the basis of the die-by-die alignment system, pressing the mold, and curing the imprint material, a relative positional deviation is generated between the pattern in the shot area and the transferred pattern after the cure. Therefore, it is necessary to inspect (overlay inspection) the relative positional deviation between the pattern in the shot area and the transferred pattern after the pattern of the mold has been transferred to the imprint material.
Accordingly, in Japanese Patent Laid-Open No. 2009-88264, a configuration in which an amount of relative positional deviation between marks formed on a base pattern on a substrate in advance and marks transferred to a resin applied to the substrate is measured by an alignment sensor provided in the imprinting apparatus is described.
When performing an overlay inspection by using a scope provided with a sensor and an optical system configured to form mark images on the sensor, if an attempt is made to detect the marks after the space between the imprint material and the mold has been increased, the alignment marks formed on the mold are positioned within a field of view of the scope. Therefore, detection accuracy for detecting the marks formed in advance in the respective shot areas required for the overlay inspection and the marks formed on the imprint material is affected.